The instant invention relates to a device for piecing up an open-end friction device equipped with two friction spinning elements, driven in the same direction, and forming a nip subjected to suction, to which a thread end is fed into a piecing position outside of the nip and is delivered therefrom into a thread forming zone in the nip. It is drawn off from said zone in the form of a continuous thread as fibers fed to the nip are incorporated into it. The invention also relates to a device to carry out this process.
In a known process of this type, the thread end is fed back from outside the nip as far as a suction nozzle by means of a guide, with the cover being open (see German published application No. 3,318,266). By means of an appropriate movement or a suitable drive of the guide, an intermediate segment of the thread is delivered to the nip of the friction spinning elements which formerly have been stopped. The cover is then closed and the thread draw-off is switched on. The friction spinning elements are again driven and the fiber feeding is started so that the fibers reach the nip at the same time as the thread end. Since the desired amount of fibers fed does not get into the nip all at once but only gradually, a thin segment of thread cannot be avoided following the point where the thread end is combined with the fibers. Such a thin segment leads to increased thread breakage because of lower strength. However, if the fiber feeding starts up before the thread end is pulled out of the suction nozzle, and gets into the nip, a long joint, constituting a thick segment is formed, and this is undesirable for reasons of appearance.